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<TITLE>Magic-7.3 Command Reference</TITLE>
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<H1> <IMG SRC=graphics/magic_title2.gif ALT="Magic VLSI Layout Tool Version 7.3">
     <IMG SRC=graphics/magic_OGL_sm.gif ALIGN="top" ALT="*"> </H1>

<H2>extresist</H2>
<HR>
Patch the extraction <TT>.ext</TT> files with detailed route resistance
information.
<HR>

<H3>Usage:</H3>
   <BLOCKQUOTE>
      <B>extresist</B> <I>option</I> <BR><BR>
      <BLOCKQUOTE>
         where <I>option</I> may be one of the following:
	 <DL>
	   <DT> <B>tolerance</B> <I>value</I>
	   <DD> Set the ratio between resistor and transistor tolerance
		for determining when to insert resistance into a network route.
	   <DT> <B>all</B>
	   <DD> Extract all the nets.
	   <DT> <B>simplify</B> [<B>on</B>|<B>off</B>]
	   <DD> Turn on/off simplification of resistor nets.
	   <DT> <B>extout</B> [<B>on</B>|<B>off</B>]
	   <DD> Turn on/off writing of the <TT>.res.ext</TT> file.
	   <DT> <B>lumped</B> [<B>on</B>|<B>off</B>]
	   <DD> Turn on/off writing of updated lumped resistances.
	   <DT> <B>silent</B> [<B>on</B>|<B>off</B>]
	   <DD> Turn off/on printing of net statistics.
	   <DT> <B>skip</B> <I>mask</I>
	   <DD> Don't extract types indicated in the comma-separated list <I>mask</I>
	   <DT> <B>box</B> <I>type</I>
	   <DD> Extract the signal under the cursor box on layer <I>type</I>
	   <DT> <B>cell</B> <I>cellname</I>
	   <DD> Extract the network for the cell named <I>cellname</I>
	   <DT> <B>geometry</B>
	   <DD> Extract network geometry and present as a collection of line
		elements on the layout.
	   <DT> <B>fasthenry</B> [<I>freq</I>]
	   <DD> Extract subcircuit network geometry into a <B>fasthenry</B>-format
		<TT>.fh</TT> file.  If <I>freq</I> is specified, the file will
		be customized for <B>fasthenry</B> analysis at the indicated
		frequency (in Hz).
	   <DT> <B>help</B>
	   <DD> Print help information
	 </DL>
      </BLOCKQUOTE>
   </BLOCKQUOTE>

<H3>Summary:</H3>
   <BLOCKQUOTE>
      The normal flow through layout extraction into a simulation file
      treats routes as nonphysical entities, that is, with infinitesimal
      impedence through the wires.  Extraction for digital simulation
      using <B>irsim</B> generates "lumped resistances", a single
      resistance per network node that, along with the node capacitance
      to substrate, provides an <I>RC</I> time constant to approximately
      model the delay from point to point in the network node.  The
      lumped resistance model is inappropriate for analog (i.e., SPICE)
      simulation, and for digital simulation, is a poor approximation
      for branching networks, where the delay between endpoints is
      different for each pair of endpoints in the network node. <P>

      The <B>extresist</B> command provides a method for generating
      a more detailed model of resistance, in which long network
      routes and branching routes are replaced with resistor devices
      and device networks. <P>

      Using <B>extresist</B> is a multi-step process.  It is first
      necessary to run both <B>extract</B> and <B>ext2sim</B> to get
      the initial netlist (with lumped, not detailed, resistances).
      After a <TT>.sim</TT> file has been generated, the
      <B>extresist all</B> command may be run.  The output is
      a file <TT>.res.ext</TT> for each cell in the hierarchy.
      Finally, with the option <B>extresist on</B> set,
      <B>ext2sim</B> or <B>ext2spice</B> will generate the final,
      detailed simulation file. <P>

      More details on using <B>extresist</B> can be found in
      <B>magic</B> Tutorial number 8.
   </BLOCKQUOTE>

<H3>Implementation Notes:</H3>
   <BLOCKQUOTE>
      <B>extresist</B> is implemented as a built-in command in <B>magic</B>.
   </BLOCKQUOTE>

<H3>See Also:</H3>
   <BLOCKQUOTE>
      <A HREF=extract.html><B>extract</B></A> <BR>
      <A HREF=ext2sim.html><B>ext2sim</B></A> <BR>
   </BLOCKQUOTE>

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<P><I>Last updated:</I> October 21, 2004 at 10:48am <P>
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